After more than ten years of development Firefox has become one of the most popular browsers around, with a 20% share of the market and hundreds of millions of users. Creators Mozilla aren't exactly running short of ideas, though, quite the opposite: the move to a rapid release cycle, and a major update every six weeks, has seen the browser further enhanced with a host of new features.

Firefox can now view PDF files itself, for instance - no need to install a third-party tool. And it's a great viewer, too, with zoom support, document thumbnails and icons, full-screen display, printing and more.

Navigation is always quick and easy. Launch the browser and the redesigned home page gives you one-click access to key functions like "Downloads", "Bookmarks", "Add-ons" and more. While the New Tab page automatically displays thumbnails of your most recent and frequently visited sites. You don't have to browse lengthy menus, or click toolbar buttons any more - you can find your favourite sites at a glance, and open them with a click.

Maybe you're concerned about security? The program will now alert you if something tries to change the default search provider, without your permission. It can block outdated web plugins - Flash, Java and so on - from opening content, helping to protect you from exploits. And maintaining your online privacy is now easier than ever, as Firefox can open a private browsing tab without interrupting the rest of your browser session.

The interface is regularly being refined to make it simpler and more usable. Tracking your downloads is easier than ever, for example: a tiny icon to the right of the address bar keeps you up-to-date with download progress, and you can now manage your downloads, history, tags and bookmarks from the same Firefox Library screen.

The future is looking very interesting, too, with regular low-level updates giving the browser even more powers. So a new "Social API" means you'll be able to access Facebook directly from Firefox, for example, without having to visit the Facebook website, while the new WebRTC framework adds direct support for in-browser audio and video chats.

And of course all this is built on an already strong foundation, absolutely packed with essential features: a powerful search bar, easy-to-use tabbed interface, password manager, pop-up blocker, integrated web search, RSS feed reader, comprehensive security and privacy tools, and a vast collection of the best browser addons you'll find anywhere.

Firefox still has plenty of strong competition, of course, in particular from Google's Chrome. But the browser is also fast, easy to use and absolutely packed with features, and if you've not tried it recently then Firefox definitely merits another look.